batgrbproduct Analysis for Trigger=508855
Analysis Summary
Notes:
- 1) No attempt has been made to eliminate the non-significant decimal places.
- 2) This batgrbproduct analysis is done of the amount of data for this trigger downloaded to date.
- 3) This batgrbproduct analysis is using the flight position for the mask-weighting calculation.
- 4) This page will be updated for up to 10 downlinks after the trigger.
======================================================================
BAT GRB EVENT DATA PROCESSING REPORT
Process Script Ver: batgrbproduct v2.46
Process Start Time (local time): Fri Dec 2 21:23:48 EST 2011
Host Name: gcn5
Current Working Dir: /local/data/raid16/prebascript_archive/trigger508855/GCN5_download_cron
======================================================================
Trigger: 00508855 Segment: 000
BAT Trigger Time: 344511889.472 [s; MET]
Trigger Stop: 344511905.856 [s; MET]
UTC: 2011-12-02T09:44:41.838580 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 290.64323700904 Dec: -17.2670380849638 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.89
Image Trigger?: NO
Rate S/N Ratio: 12.4096736459909 [ if not an image trigger ]
Image S/N Ratio: 8.89
Flight Position: [ source = BAT ]
RA: 290.64323700904 Dec: -17.2670380849638 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 290.655962386563 Dec: -17.2697512633888 [deg; J2000]
{ 19h 22m 37.4s , -17d 16' 11.1" }
+/- 2.49087612910464 [arcmin] (estimated 90% radius based on SNR)
+/- 1.0017919939633 [arcmin] (formal 1-sigma fit error)
SNR: 8.25849766732478
Angular difference between Flight and Ground position is 0.747059 arcmin
Partial Coding Fraction: 0.5390625 [ including projection effects ]
Duration
T90: 23.4919999837875 +/- 6.14926076962584
Measured from: 0.984000086784363
to: 24.4760000705719 [s; relative to TRIGTIME]
T50: 11.1279999613762 +/- 7.85127480231857
Measured from: 4.50400012731552
to: 15.6320000886917 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 1.14399999380112
to: 2.14399999380112 [s; relative to TRIGTIME]
Total Fluence
Measured from: -2.18400001525879
to: 25.0239999890327 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.505248 0.093719 0.056239 -0.014702
0.042573 0.040654 0.035511 0.031089 [error]
Peak 0.049352 0.007756 0.012523 0.001171
0.008636 0.007914 0.006769 0.006025 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
=== Fluence/Peak Flux Summary ===
Model Band1 Band2 Band3 Band4 Band5 Total
15-25 25-50 50-100 100-350 15-150 15-350 keV
Fluence Power-law 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Power-law 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Fluence Cutoff-PL 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Cutoff-PL 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Fluence Band 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.000 0.000 - - 0.00e+00 0.00e+00 0.000 0
CPL 1.000 0.000 50.0 0.0 3.36e-03 0.00e+00 104.050 56
The chi2 of BB fit is 39.33 which shows a significant improvement in the fit over a PL.
Check the BB fit.
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.000 0.000 - - 0.00e+00 0.00e+00 0.000 0
CPL -6.395 0.000 17.6 4.4 2.64e+05 0.00e+00 58.050 56
Model : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index : photon index: E^-{Ph_index} (minus sign is not included in the index)
Ph_90err : 90% error of the photon index
Epeak : Epeak in keV
Epeak_90err: 90% error of Epeak
Norm : normalization at 50 keV in PL model and at 1 keV in CPL model
Nomr_90err : 90% error of the normalization
chi2 : Chi-Squared
dof : degree of freedom
=== T90/T50 calculation in the 50-300 keV band (BATSE band) using 64 ms lc ===
T90 in the 50-300 keV band: 0.000000 sec.
T50 in the 50-300 keV band: 0.000000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 27.208 -2.184 25.024
T90 23.492 0.984 24.476
T50 11.128 4.504 15.632
Peak 1.000 1.144 2.144
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
290.6560 -17.2698 0.0233 37.8 -31.1 0.6373 8.3 TRIG_00508855
------------------------------------------
Foreground time interval of the image:
-2.184 25.024 (delta_t = 27.208 [sec])
Background time interval of the image:
-239.472 -183.582 (delta_t = 55.890 [sec])
-182.472 -31.072 (delta_t = 151.400 [sec])
-29.472 -2.184 (delta_t = 27.288 [sec])
Lightcurves
Notes:
- 1) All plots contain as much data as has been downloaded to date.
- 2) The mask-weighted light curves are using the flight position.
- 3) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
- 4) For all the mask-weighted lightcurves, the y-axis units are counts/sec/det where a det is 0.4 x 0.4 = 0.16 sq cm.
- 5) The verticle lines correspond to following: green dotted lines are T50 interval, black dotted lines are T90 interval, blue solid line(s) is a spacecraft slew start time, and orange solid line(s) is a spacecraft slew end time.
- 6) Time of each bin is in the middle of the bin.
1 s binning
From T0-310 s to T0+310 s
From T100_start - 20 s to T100_end + 30 s
Full time interval
64 ms binning
Full time interval
From T100_start to T100_end
From T0-5 sec to T0+5 sec
16 ms binning
From T100_start-5 s to T100_start+5 s
8 ms binning
From T100_start-3 s to T100_start+3 s
2 ms binning
From T100_start-1 s to T100_start+1 s
SN=5 or 10 sec. binning (whichever binning is satisfied first)
SN=5 or 10 sec. binning (T < 200 sec)
Spectra
Notes:
- 1) The fitting includes the systematic errors.
- 2) For long bursts, a spectral fit of the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
- 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.
- 4) For short bursts (T90<1sec), the specrtum is also fit with Blackbody, OTTB, and Double Blackbody.
Time averaged spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -2.184 sec. to 25.024 sec.
XSPEC12>exit
XSPEC: quit
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: ( )
Norm@50keV : ( )
------------------------------------------------------------
Photon flux (15-150 keV) in 27.21 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.184 sec. to 25.024 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.00000 ( )
Epeak [keV] : 50.0000 ( )
Norm@50keV : 3.35851E-03 ( )
------------------------------------------------------------
# Chi-Squared = 104.05 using 59 PHA bins.
# Reduced chi-squared = 1.8580 for 56 degrees of freedom
# Null hypothesis probability = 1.019312e-04
Photon flux (15-150 keV) in 27.21 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from -2.184 sec. to 25.024 sec.
XSPEC12>exit
XSPEC: quit
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : ( )
beta : ( )
Epeak [keV] : ( )
Norm@50keV : ( )
------------------------------------------------------------
Photon flux (15-150 keV) in 27.21 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 2.58381 (-0.362705 0.43613)
R^2/D10^2 : 105.990 (-105.988 216.322)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
# Chi-Squared = 39.33 using 59 PHA bins.
# Reduced chi-squared = 0.6899 for 57 degrees of freedom
# Null hypothesis probability = 9.642185e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.004e-07 9.869e-08
25- 50 1.680e-08 1.055e-08
50-150 7.292e-12 8.408e-12
15-150 2.172e-07 1.125e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 4.93454 (-1.07704 1.5537)
Norm : 65.3472 (-38.7577 105.824)
------------------------------------------------------------
# Chi-Squared = 39.72 using 59 PHA bins.
# Reduced chi-squared = 0.6968 for 57 degrees of freedom
# Null hypothesis probability = 9.603351e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.959e-07 9.344e-08
25- 50 2.403e-08 1.333e-08
50-150 1.165e-10 1.265e-10
15-150 2.201e-07 1.143e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 2.48956 (-0.38179 0.433115)
R1^2/D10^2 : 133.710 (-66.8566 146.595)
kT2 [keV] : 20.8150 (-13.9961 -20.8151)
R2^2/D10^2 : 1.81621E-03 (-0.00181191 0.110542)
------------------------------------------------------------
# Chi-Squared = 35.32 using 59 PHA bins.
# Reduced chi-squared = 0.6422 for 55 degrees of freedom
# Null hypothesis probability = 9.820216e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.977e-07 1.084e-07
25- 50 3.475e-08 1.909e-08
50-150 6.698e-08 5.090e-08
15-150 2.994e-07 1.581e-07
Peak spectrum fit
Power-law model
Time interval is from 1.144 sec. to 2.144 sec.
XSPEC12>exit
XSPEC: quit
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: ( )
Norm@50keV : ( )
------------------------------------------------------------
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.144 sec. to 2.144 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -6.39461 ( )
Epeak [keV] : 17.6007 ( -4.57774 4.24001 )
Norm@50keV : 2.63852E+05 ( )
------------------------------------------------------------
# Chi-Squared = 58.05 using 59 PHA bins.
# Reduced chi-squared = 1.037 for 56 degrees of freedom
# Null hypothesis probability = 3.998245e-01
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from 1.144 sec. to 2.144 sec.
XSPEC12>exit
XSPEC: quit
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : ( )
beta : ( )
Epeak [keV] : ( )
Norm@50keV : ( )
------------------------------------------------------------
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 3.80920 (-0.89658 1.25192)
R^2/D10^2 : 22.2478 (-22.2478 76.2678)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
# Chi-Squared = 59.12 using 59 PHA bins.
# Reduced chi-squared = 1.037 for 57 degrees of freedom
# Null hypothesis probability = 3.979500e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.589e-08 9.260e-09
25- 50 4.978e-09 3.444e-09
50-150 4.471e-11 4.750e-11
15-150 2.091e-08 1.217e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 10.6200 (-4.64946 15.1748)
Norm : 19.8991 (-19.8982 51.5121)
------------------------------------------------------------
# Chi-Squared = 59.97 using 59 PHA bins.
# Reduced chi-squared = 1.052 for 57 degrees of freedom
# Null hypothesis probability = 3.685560e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.483e-08 8.940e-09
25- 50 6.907e-09 4.630e-09
50-150 5.558e-10 6.230e-10
15-150 2.229e-08 1.383e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 3.54914 (-0.927671 1.23442)
R1^2/D10^2 : 30.0508 (-19.216 132.887)
kT2 [keV] : 21.0802 (-21.1401 -21.1401)
R2^2/D10^2 : 7.35756E-03 (-0.00730845 0.0617782)
------------------------------------------------------------
# Chi-Squared = 56.60 using 59 PHA bins.
# Reduced chi-squared = 1.029 for 55 degrees of freedom
# Null hypothesis probability = 4.151099e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.546e-08 8.965e-09
25- 50 6.935e-09 3.493e-09
50-150 1.055e-08 8.460e-09
15-150 3.295e-08 1.784e-08
Plot creation:
Fri Dec 2 21:35:35 EST 2011